redirect to gh-pages: add doc

[degenaro]

Issue description / feature objectives

re: PR #1777 follow-up suggestions

1. In trestle docs, document how to test
2. In trestle docs, document how to utilize different versions

Caveats / Assumptions

Suggestions make sense and have not already been done.

Completion Criteria

treslte docs comprise gh-pages testing and utilization info.

[github-actions]

This issue has been automatically marked as stale because it has not had activity within 90 days. It will be automatically closed if no further activity occurs within 30 days.